First, you need to get your hands on a food called "Apple Ice Cream". The earliest you'll get this is in the inn at Ravennue village.
Buy and eat one to learn the recipe, then go back to Bose's market to buy as much of the ingredients as possible.
One of each ingredient equals to about 80 something mira while the ice cream itself can be sold for 125 mira.
If you mass produce 99 of it and sell it back to the market, you can make 4000 something mira per 99 ice creams sold.
Repeat until satisfied and when funds start to drain. No more selling your precious sepith! <img src="http://staticneo.com/neoassets/smileys/smile.gif" border=0 vspace=2 alt="" />
After defeating the final boss and now wander the streets of Grancel, if you should talk to two people around town, you'll encounter a reference and a short 4th wall breaking session.
The reference requires you to talk to a man in front of the Inn in town, taking a picture of his daughter. Talk to him and he'll tell his kid to smile and say "Fuzzy Pickles!". Get it? This is a reference to the random photographer from the old cult favorite game of EarthBound!
The fourth wall breaking is found in the Liberl News building by talking to Dorothy at the desk. She will mention being legible to the "Fuelitzer" prize. Estelle questions that and asks if she meant the "Pul-" until Joshua stops her abruptly by saying "Shhh! You want to get sued?". It's an easy guess to think she meant the "Pulitzer" prize.